000
AXPZ20 KNHC 221601
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED SEP 22 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

...SPECIAL FEATURE...

TROPICAL DEPRESSION GEORGETTE WAS CENTERED OVER THE GULF OF 
CALIFORNIA NEAR 26.8N 110.0W AT 22/1500 UTC MOVING NNW AT 12 KT. 
MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. ESTIMATED 
MINIMUM CENTRAL PRESSURE IS 1000 MB. THE DEPRESSION IS CHARACTERIZED
AS A LARGE CIRCULAR SHAPE AREA OF VERY DEEP CONVECTION WITHIN 
150 NM OF THE CENTER IN THE NW QUADRANT AS IT MOVES OVER THE 
WARM WATERS OF THE GULF OF CALIFORNIA...WITH SPEED DIVERGENCE ALOFT. 
GEORGETTE IS FORECAST TO CONTINUE MOVING ACROSS THE NORTHERN PORTION
THROUGH THIS AFTERNOON...THEN INLAND THE NW PORTION OF MEXICO
EARLY TONIGHT. IT WILL CONTINUE TO WEAKEN OVERNIGHT INTO THU MORNING
...THEN DISSIPATE FRI MORNING. MAIN THREAT FROM GEORGETTE WILL 
STILL BE THE POTENTIAL FOR HEAVY RAINFALL AMOUNTS OVER THE WESTERN
PORTIONS OF THE STATE OF SONORA WHICH MAY LEAD TO LIFE-THREATENING
FLASH FLOODS AND MUD SLIDES. REMNANT MOISTURE FROM GEORGETTE WILL
THEN SPREAD INTO PORTIONS OF THE SOUTHWESTERN U.S. OVER THE NEXT
COUPLE OF DAYS. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP2/WTPZ22 KNHC AND WTPZ32 KNHC FOR MORE DETAILS.

...ITCZ/MONSOON TROUGH...

MONSOONAL S TO SW WIND FLOW DOMINATES THE DEEP TROPICS ACROSS THE 
AREA. A MONSOON TROUGH AXIS WAS ANALYZED FROM 13N107W TO A 1010 MB
LOW NEAR 13N118W TO 12N125W TO A 1012 MB LOW NEAR 12N131W THEN
TO 11N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN
120 NM S OF THE TROUGH BETWEEN 115W-123W. SCATTERED MODERATE 
CONVECTION IS WITHIN 90 NM S OF THE TROUGH BETWEEN 127W-131W.

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE IS OVER FAR NE MEXICO WITH A RIDGE
SW TO 23N120W AND W TO ANOTHER ANTICYCLONE NEAR 24N133W. TO THE
N OF THE RIDGE...A MID/UPPER LEVEL TROUGH IS PRESENT N OF 25N 
E OF 128W WITH ITS AXIS FROM 28N119W NW TO N OF AREA AT 32N...AND
TO OVER THE PACIFIC NW U.S. TO THE S OF THE RIDGE...UPPER LEVEL NE
TO E MODERATE FLOW IS PRESENT WITH A DIFFLUENT FLOW PATTERN 
SUSTAINING CONVECTION E OF ABOUT 109W. ELSEWHERE S OF THE MONSOON 
TROUGH...CONVECTION IS INDUCING UPPER LEVEL DIVERGENCE IN THE ELY 
FLOW ALOFT W OF 109W. STRONG UPPER DIVERGENCE IS ALSO BEING INDUCED 
BY A LARGE CLUSTER OF SCATTERED MODERATE TO STRONG CONVECTION 
OCCURRING S OF THE GULF OF TEHUANTEPEC FROM 11N TO 15N BETWEEN 92W 
AND 102W. THIS AREA OF CONVECTION HAS BECOME MORE CONCENTRATED 
DURING THE PAST 24 HOURS AS IT MOVES WNW AROUND 8 KT.

AT THE SURFACE TO LOW LEVELS BROAD HIGH PRESSURE DOMINATES THE 
SUBTROPICS N OF 19N W OF 120W...WITH A SURFACE HIGH OF 1020 MB W OF
THE AREA NEAR 29N142W WITH ITS ASSOCIATED RIDGE EXTENDING ESE TO
NEAR 28N127W. THE INTERACTION BETWEEN THE RIDGE AND BROAD LOW PRES
E OF 122W WHERE TROPICAL DEPRESSION GEORGETTE IS LOCATED CONTINUES 
TO SUPPORT NW TO N 20 KT N OF 25N E OF 120W TO THE BAJA PENINSULA 
COAST. AS GEORGETTE CONTINUES TO WEAKENS AND LIFT OUT TO THE N...THE 
GRADIENT WILL RELAX WITH WINDS DIMINISHING TO LESS THAN 20 KT AND 
SEAS SUBSIDING TO LESS THAN 8 FT IN ABOUT 26 HOURS. MONSOONAL FLOW 
DOMINATES THE TROPICS E OF 130W WITH SEVERAL LOWS SPINNING UP WITHIN 
THE MONSOON TROUGH AS DESCRIBED ABOVE...ALL GENERALLY MOVING 
EASTWARD. SWLY WINDS ON THE S SIDE OF THE TROUGH AXIS ARE AROUND 20 
KT OVER THE WATERS FROM 08N TO 13N BETWEEN 100W AND 125W. ABUNDANT 
TROPICAL MOISTURE CONVERGING ON THE S SIDE OF THE MONSOON TROUGH IS 
EXPECTED TO LINGER THROUGH AT LEAST THE NEXT 48 HOURS...AND PERHAPS
SPREAD EASTWARD INTO THE SW CARIBBEAN THEREAFTER.

$$
AGUIRRE